Updated the instructions to compile in RelWithDebInfo mode.
Updated the instructions to compile in RelWithDebInfo mode.

sheim/drake,sheim/drake,billhoffman/drake,sheim/drake,billhoffman/drake,sheim/drake,billhoffman/drake,sheim/drake,billhoffman/drake,billhoffman/drake,sheim/drake,sheim/drake,billhoffman/drake,billhoffman/drake,sheim/drake,billhoffman/drake